A backlight module provides a light source to a liquid crystal (LC) panel. As shown in FIG. 1, a control scheme of a backlight driving circuit of the backlight module may use a microcontroller (MCU). Subject to characteristics of the MCU, the MCU first needs a power supply from a power end of the backlight driving circuit, and then receives a monitoring signal output by an external monitoring device. The monitoring signal includes an enable signal controlling a conversion device to turn on or turn off and a dimming signal adjusting a backlight brightness of a liquid crystal display (LCD). If the MCU first receives the monitoring signal, and then is provided with the power supply, the MCU may work abnormally or be damaged. To avoid time sequencing errors when the MCU first is provided with the power supply and then receives the monitoring signal, the MCU needs to maintain power for a long time, which results in the MCU working even in a stand-by state, thus increasing stand-by power, and does not completely avoid the time sequencing errors of the monitoring signal in use of the MCU. If the monitoring signal is input the MCU prior to the power supply, the MCU does not work normally.